Re: Stanley 20 hp boiler, retubing
Posted by:
David K. Nergaard (IP Logged)
Date: January 05, 2002 11:24AM
<HTML>Generally, if the wire looks good, no signs of rust or motion at the ends, it probably is good. If it is kept dry so it will not rust, it will probably out last the rest of the boiler.
A test I use, which is admittedly not universally approved, is to use a test pressure high enough to be well above the yield strength of the shell alone. This forces the wire to take the load. If there is anything wrong with the wire, it will start to unwind and you will hear it moving. If so, you can immediately dump the pressure before the shell is damaged. This test has the advantage that one does not have to remove the insulation to test the wire, you should hear any thing happening through the covering. I have used 1500 psi. Of course, you should not expose the steam pressure gauge, steam automatic, safety valve or the "brass bottle" water level gauge to this pressure. Remove them or otherwise shut off their connections.</HTML>